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Abstract: A novel micro CCHP system, which is based on a two bed silica gel–water adsorption chiller, is constructed in this work. To reveal the chiller characteristic in this system, a transient model of the adsorption chiller is developed. According to the comparison of the simulated results and experimental data, the presented model shows a good performance in predicting the chiller performance, with both stable and variable heat source temperature. With the analysis of simulated results, it is found that the cooling capacity and the coefficient of performance (COP) of the chiller are influenced significantly by the average value and variation rate of electric load, as well as the average value of cooling load. The water tank also shows a great effect on the chiller performance. To get better performance of the chiller, the water tank should be adopted when the electric load is low or its variation rate is positive, and should not be utilized when the electric load is high or its variation rate is negative. A 500 L water tank is recommended in order to get better performance and acceptable start-up time. Furthermore, to get better performance as well as higher security, a cold accumulator should be adopted. [Copyright &y& Elsevier]

Abstract: In this paper, a transient model of a silica gel–water adsorption chiller, which is developed in Shanghai Jiao Tong University (SJTU), is developed in order to simulate the evaporating, condensing, and adsorption temperature. Furthermore, this model is verified by a series of experiments. The theoretical studies and experimental data show that the coefficient of performance (COP) is influenced significantly by the variation rates of the heat source temperatures. The results also show that when this chiller is driven by solar energy, a buffer tank should be adopted in the system in order to get better performance when solar insolation is low, and should not be utilized when solar insolation is high, otherwise low COP will be gotten for the reason of the consumption of high electric energy. [Copyright &y& Elsevier]

Abstract: Adsorption performances and thermal conductivity were tested for three types of adsorbent: Pure CaCl2 powder, simple composite adsorbent and consolidated composite adsorbent. The simple composite adsorbents show better adsorption performance because the additive of expanded graphite in CaCl2 powder has restrained the agglomeration phenomenon in adsorption process and improved the adsorption performance of CaCl2. The consolidated composite adsorbent are suitable to be used as adsorbent for ice maker on fishing boats because they have higher thermal conductivity, larger volumetric cooling capacity, higher SCP values and better anti-sway performance than simple composite adsorbents. Thermal conductivity of the consolidated composite adsorbent is 6.5–9.8Wm−1 K−1 depending on the molding pressure, ranging from 5 to 15MPa, which is about 32 times higher than the thermal conductivity of CaCl2 powder. The volumetric cooling capacity of consolidated composite adsorbent is about 52% higher than the best result obtained for CaCl2 at the evaporating temperature of −10°C. The SCP of the consolidated adsorbent increases of about 353% than CaCl2 powder from simulation results at T ad=30°C and T ev=−10°C. The consolidated composite adsorbents have good anti-sway performance and they are not easy to be scattered out when the fishing boats sway on the sea. [Copyright &y& Elsevier]

Abstract: The prototype of a novel silica gel–water adsorption chiller is built and its performance is tested in detail. The experimental results show that the refrigerating capacity (RC) and COP of the chiller are 7.15 and 0.38kW, respectively, when the hot water temperature is 84.8°C, the cooling water temperature is 30.6°C, and the chilled water outlet temperature is 11.7°C. The RC will reach 6kW under the condition of 65°C hot water temperature, 30.5°C cooling water temperature and 17.6°C chilled water temperature. The results confirm that this kind of adsorption chiller is an effective refrigerating machine though its performance is not as fine as the prediction results. Also it is well effectively driven by a low-grade heat source. Therefore, its applications to the low-grade heat source are much attractive. [Copyright &y& Elsevier]

Abstract: A novel CaCl2/expanded graphite-NH3 adsorption refrigerator is developed and tested. Only three valves are installed in this refrigerator and they all work at the same positive pressure condition, so the operating reliability of the refrigerator is greatly improved. The experimental results show that the refrigerating power QCP, COP, SCP, electricity COPEl, and volume refrigerating density QCP-V of the refrigerator are 11.4kW, 0.27, 422.2W/kg, 32.6 and 57kW/m3, respectively, under the following conditions: the temperature of heating vapor is from 120°C to 140.3°C, the cooling water temperature is 25°C, the evaporation temperature is −15°C, the heating/cooling time is 25min including 45s mass recovery time. The SCP and volume refrigerating density of this refrigerator are about 1.8times and 1.5times that of the maximum of the former test results by other researchers. [Copyright &y& Elsevier]

Abstract: A novel silica gel–water adsorption chiller is designed and its performance is predicted in this work. This adsorption chiller includes three vacuum chambers: two adsorption/desorption (or evaporation/condensation) vacuum chambers and one heat pipe working vacuum chamber as the evaporator. One adsorber, one condenser and one evaporator are housed in the same chamber to constitute an adsorption/desorption unit. The evaporators of two adsorption/desorption units are combined together by a heat-pipe heat exchanger to make continuous refrigerating capacity. In this chiller, a vacuum valve is installed between the two adsorption/desorption vacuum chambers to increase its performance especially when the chiller is driven by a low temperature heat source. The operating reliability of the chiller rises greatly because of using fewer valves. Furthermore, the performance of the chiller is predicted. The simulated results show that the refrigerating capacity is more than 10kW under a typical working condition with hot water temperature of 85°C, the cooling water temperature of 31°C and the chilled water inlet temperature of 15°C. The COP exceeds 0.5 even under a heat source temperature of 65°C. [Copyright &y& Elsevier]

Abstract: An experimental investigation of the performance of a micro-combined cooling, heating and power (CCHP) system is described. The natural gas and LPG-fired micro-CCHP system uses a small-scale generator set driven by a gas engine and a new small-scale adsorption chiller, which has a rated electricity power of 12kW, a rated cooling of 9kW and a rated heating capacity of 28kW. Silica gel–water is used as working pair in the adsorption cooling system. The refrigeration COP of the adsorption chiller is over 0.3 for 13°C evaporation temperature. The test facility designed and built is described, which supplies better test-rig platform for cooling, heating and power cogeneration. Experimental methodology of this system is presented and the results are discussed. An energetic analysis of micro-CCHP system is performed as well. The overall thermal and electrical efficiency is over 70%. [Copyright &y& Elsevier]

Abstract: A new type of adsorber for an adsorption ice maker on fishing boats, which uses a compound adsorbent (activated carbon and CaCl2) and ammonia working pair, is designed. This type of heat pipe adsorber solves the problem of incompatibility between ammonia, copper, seawater and steel. The heating/cooling power for the adsorption/desorption process of the adsorbent, which is required to be transferred by one heat pipe in the adsorber, is computed by the test results of the adsorbent, and the heat transfer performance of one heat pipe in the adsorber is simulated according to the theory of the two phase closed thermosyphon. The heat transfer performance of the heat pipe can meet the heat demands for adsorption/desorption of the adsorbent when the evaporating temperature is −15°C and the cycle time is 10min. A test unit is set up to test the heating/cooling performance of the heat pipe type adsorber, and the experimental results are coincident with the simulation. The performance of a two bed adsorption ice maker with heat pipe adsorbers is predicted, and the cooling power is about 17.1–17.8kW at the evaporating temperature of −15°C and cycle time of 10min with mass recovery between two 29kg compound adsorbent beds. [Copyright &y& Elsevier]

Adsorption performances of three types of adsorbents, CaCl2 with different expansion space, simple compound adsorbent and solidified compound adsorbent made by CaCl2 and activated carbon, are tested, in which ammonia is used as refrigerant. The solidified compound adsorbent shows the best performance for adsorption ice makers on fishing boats for the larger filling quantity of adsorbent in adsorber. The mass transfer performance is improved by the additive of activated carbon in solidified compound adsorbent at the condition of low evaporating temperature. The volume cooling density of solidified compound adsorbent is about 35% improved at least in comparison with the optimal results of CaCl2 at the evaporating temperature of −15 °C. [Copyright &y& Elsevier]

Abstract: Three types of heat pipe type adsorption systems, which were designed for conserving fish on fishing boats, were studied aimed to settle the corrosion between seawater and steel adsorber for ammonia refrigeration system, as well as to improve the refrigeration performance. Three test units, which were one thermosyphon type adsorber test unit and two split heat pipe type adsorption refrigeration systems, were set up, and the second generation split heat pipe type system that has the function of heat pipe liquid pumping showed the better refrigeration performance, and it also could solve the corrosion problems of adsorber more effectively. At the evaporating temperature of −15°C, its average specific cooling power per kilogram CaCl2 of each adsorber SCP=731Wkg−1. On the basis of the research work on heat pipe type systems, a split heat pipe type adsorption ice maker, whose COP and SCP were 0.3 and 458.5Wkg−1, respectively, has been developed. [Copyright &y& Elsevier]